Indometacin

For an informed discussion with your doctor or pharmacist. This information collection is not a clinically validated interaction checker. Missing data do not establish safety. Do not change or stop prescribed medicines on the basis of this information. The findings apply to the specific conditions studied; laboratory and animal studies cannot be directly extrapolated to humans.

Active substance: Indometacin

Examples of brand names: Amuno [DE]

ATC code: M01AB01

Main use (for orientation): Pain; inflammation

Documented research summary

A very small human pilot provides limited signals of attenuation of individual marijuana effects, but no clinical pharmacokinetic quantification. Preclinical COX-dependent effects strongly depend on endpoint, vessel and model. No antidote/protection recommendation or assurance of safety for rare cannabinoids.

Uncertainties and limitations

Does not establish safety for less-studied cannabinoids or untested formulations/doses.

Do not infer clinical dosage from preclinical effects or enzyme hypotheses.

Separately recorded findings

7 separately recorded findings. Each statement applies to its documented study context.

THC (marijuana smoke) – clinically investigated

Finding ID: B0388

Type of result: Very limited clinical evidence

Observation: Indometacin moderately reduced subjective high and heart-rate increase and abolished changes in time perception; impaired word recall persisted.

Mechanism: Prostaglandin-dependent pharmacodynamics, exploratory.

Study type: Single-blind placebo-controlled human pilot, n=4; abstract

Context studied: Indometacin pretreatment before smoked marijuana; THC/PGE2 measured, but quantitative pharmacokinetic results absent from abstract.

Clinical interpretation: Endpoint- and model-specific

Limitations and uncertainties: Not antidote evidence or an intoxication-treatment recommendation. Small sample and missing full text.

Original sources for this finding: Antagonism of marihuana effects by indomethacin in humans. [C_PR_1846934]

CBD – laboratory and animal studies

Finding ID: B0389

Type of result: Preclinical evidence

Observation: Indometacin 10 µM reduced CBD relaxation of isolated human pulmonary arteries; at CBD 30 µM, maximum relaxation fell from approximately 90% to 45%.

Mechanism: COX-dependent ex-vivo vascular relaxation.

Study type: Ex-vivo human tissue; mechanistic organ-bath study

Context studied: Lung resection specimens from 32 donors overall; indometacin condition n=5 vessel samples; 30-minute pre-incubation.

Clinical interpretation: Endpoint- and model-specific

Limitations and uncertainties: Human tissue is not a clinical combination study. Other vascular territories may respond differently; no blood-pressure prediction.

Original sources for this finding: Vasodilatory effects of cannabidiol in human pulmonary and rat small mesenteric arteries: modification by hypertension and the potential pharmacological opportunities. [C_PR_31800399]

CBD – laboratory and animal studies

Finding ID: B0390

Type of result: Preclinical evidence

Observation: Indometacin abolished or reduced certain CBD-improved acetylcholine relaxations in mesenteric arteries of hypertensive or diabetic rats; aortic effects differed.

Mechanism: COX/NO-dependent endothelium-mediated responses after CBD pretreatment.

Study type: In-vivo CBD followed by ex-vivo indometacin assessment

Context studied: CBD 10 mg/kg intraperitoneally for 14 days (hypertension) or 7 days (ZDF); indometacin in the organ bath, not systemic co-administration.

Clinical interpretation: Endpoint- and model-specific

Limitations and uncertainties: Not a clinical interaction. Potency and maximum response differ in the hypertension full text; indiscriminate complete blockade in all vessels would be incorrect.

Original sources for this finding: Vasoprotective Endothelial Effects of Chronic Cannabidiol Treatment and Its Influence on the Endocannabinoid System in Rats with Primary and Secondary Hypertension. [C_PR_34832902]; In Vivo Cannabidiol Treatment Improves Endothelium-Dependent Vasorelaxation in Mesenteric Arteries of Zucker Diabetic Fatty Rats. [C_PR_28572770]

THC – laboratory and animal studies

Finding ID: B0391

Type of result: Preclinical evidence

Observation: Indometacin blocked THC dilation in rabbit cerebral arterioles and reduced relaxation in hypertensive rat mesenteric arteries; by contrast, it enhanced THC relaxation in isolated rat aorta and inhibited vasoconstriction there.

Mechanism: Context-dependent COX-mediated vascular pharmacodynamics.

Study type: Animal/ex-vivo experiments; abstracts

Context studied: Different vascular territories, disease models and routes; often indometacin 10 µM.

Clinical interpretation: Endpoint- and model-specific

Limitations and uncertainties: Direction dependence prevents a uniform clinical blood-pressure conclusion. THC showed a pressor effect in vivo in the L-NAME model.

Original sources for this finding: Anandamide and delta 9-THC dilation of cerebral arterioles is blocked by indomethacin. [C_PR_8594893]; The in vitro and in vivo cardiovascular effects of Delta9-tetrahydrocannabinol in rats made hypertensive by chronic inhibition of nitric-oxide synthase. [C_PR_17284670]; Vascular effects of delta 9-tetrahydrocannabinol (THC), anandamide and N-arachidonoyldopamine (NADA) in the rat isolated aorta. [C_PR_15659311]

THC – laboratory and animal studies

Finding ID: B0392

Type of result: Preclinical evidence

Observation: Topical indometacin attenuated the THC-related decrease in intraocular pressure.

Mechanism: Prostaglandin-dependent ocular pharmacodynamics.

Study type: Rabbit experiment; abstract

Context studied: Indometacin 2% suspension 1 hour before intravenous THC.

Clinical interpretation: Endpoint- and model-specific

Limitations and uncertainties: No clinical glaucoma or oral interaction conclusion.

Original sources for this finding: Interaction between delta-9-tetrahydrocannabinol and indomethacin. [C_PR_11464074]

THC, D8THC – laboratory and animal studies

Finding ID: B0393

Type of result: Preclinical evidence

Observation: Chronic THC reduced indometacin analgesia in the mouse PPQ test; separately, indometacin antagonised D8THC-induced suppression of lever pressing in rats.

Mechanism: Experimental COX, behavioural and analgesic effects.

Study type: Animal experiments; abstracts

Context studied: Chronic THC pretreatment and acute D8THC combination are different experimental questions.

Clinical interpretation: Endpoint- and model-specific

Limitations and uncertainties: Do not use as established loss of effect in humans or reversal of intoxication.

Original sources for this finding: Decrease in efficacy and potency of nonsteroidal anti-inflammatory drugs by chronic delta(9)-tetrahydrocannabinol administration. [BMED12235269]; Behavioral suppression induced by cannabinoids is due to activation of the arachidonic acid cascade in rats. [BMED11166698]

THC – laboratory and animal studies

Finding ID: B0394

Type of result: Preclinical evidence

Observation: Indometacin inhibited THC-induced neurotoxicity in cultured hippocampal preparations; THC-mediated NK/Th1 suppression was unaffected in other experiments.

Mechanism: Cellular prostanoid-dependent and independent endpoints.

Study type: Neuronal culture, immune-cell/mouse studies; abstracts

Context studied: Different cells, exposures and endpoints; no uniform antagonistic effect.

Clinical interpretation: Endpoint- and model-specific

Limitations and uncertainties: Not clinical neuroprotection or assurance of immune-risk safety. Do not present in-vitro neurotoxicity as a proven mechanism of human memory impairment.

Original sources for this finding: Hippocampal neurotoxicity of Delta9-tetrahydrocannabinol. [BMED9651215]; Prevention and reversal of delta-9-tetrahydrocannabinol induced depression of natural killer cell activity by interleukin-2. [C_PR_2540100]; The THC-induced suppression of Th1 polarization in response to Legionella pneumophila infection is not mediated by increases in corticosterone and PGE2. [C_PR_15258190]

References and access status

[C_LABEL_D0170] INDOMETHACIN (INDOMETHACIN) CAPSULE [A-S MEDICATION SOLUTIONS]

Original source / bibliographic reference

Authors: A-S MEDICATION SOLUTIONS

Year: 2026

Source type: US Structured Product Label

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

[C_PR_1651514] Elevation of brain prostaglandin E2 levels in rodents by delta 1-tetrahydrocannabinol.

Original source / bibliographic reference

Authors: Hunter SA, Audette CA, Burstein S.

Year: 1991

Source type: Primary source, abstract read

DOI: 10.1016/0952-3278(91)90167-4

PMID: 1651514

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[C_PR_1846934] Antagonism of marihuana effects by indomethacin in humans.

Original source / bibliographic reference

Authors: Perez-Reyes M, Burstein SH, White WR, McDonald SA, Hicks RE.

Year: 1991

Source type: Primary source, abstract read

DOI: 10.1016/0024-3205(91)90465-n

PMID: 1846934

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[C_PR_2540100] Prevention and reversal of delta-9-tetrahydrocannabinol induced depression of natural killer cell activity by interleukin-2.

Original source / bibliographic reference

Authors: Specter S, Rivenbark M, Newton C, Kawakami Y, Lancz G.

Year: 1989

Source type: Primary source, abstract read

DOI: 10.1016/0192-0561(89)90100-8

PMID: 2540100

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[C_PR_2846397] Cannabinoids and pain responses: a possible role for prostaglandins.

Original source / bibliographic reference

Authors: Burstein SH, Hull K, Hunter SA, Latham V.

Year: 1988

Source type: Primary source, abstract read

DOI: 10.1096/fasebj.2.14.2846397

PMID: 2846397

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[C_PR_6311573] Possible role of prostaglandins in the effects of the cannabinoids on adenylate cyclase activity.

Original source / bibliographic reference

Authors: Hillard CJ, Bloom AS.

Year: 1983

Source type: Primary source, abstract read

DOI: 10.1016/0014-2999(83)90357-6

PMID: 6311573

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[C_PR_8594893] Anandamide and delta 9-THC dilation of cerebral arterioles is blocked by indomethacin.

Original source / bibliographic reference

Authors: Ellis EF, Moore SF, Willoughby KA.

Year: 1995

Source type: Primary source, abstract read

DOI: 10.1152/ajpheart.1995.269.6.h1859

PMID: 8594893

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[BMED9651215] Hippocampal neurotoxicity of Delta9-tetrahydrocannabinol.

Original source / bibliographic reference

Authors: Chan GC, Hinds TR, Impey S, Storm DR.

Year: 1998

Source type: Publication; title and abstract reviewed

DOI: 10.1523/jneurosci.18-14-05322.1998

PMID: 9651215

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

PubMed – bibliographic reference / abstract

PubMed Central – archived text

DOI – publisher access (access restrictions may apply)

[BMED11166698] Behavioral suppression induced by cannabinoids is due to activation of the arachidonic acid cascade in rats.

Original source / bibliographic reference

Authors: Yamaguchi T, Shoyama Y, Watanabe S, Yamamoto T.

Year: 2001

Source type: Publication; title and abstract reviewed

DOI: 10.1016/s0006-8993(00)03127-9

PMID: 11166698

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

PubMed – bibliographic reference / abstract

DOI – publisher access (access restrictions may apply)

[C_PR_11464074] Interaction between delta-9-tetrahydrocannabinol and indomethacin.

Original source / bibliographic reference

Authors: Green K, Kearse EC, McIntyre OL.

Year: 2001

Source type: Primary source, abstract read

DOI: 10.1159/000055673

PMID: 11464074

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[BMED12235269] Decrease in efficacy and potency of nonsteroidal anti-inflammatory drugs by chronic delta(9)-tetrahydrocannabinol administration.

Original source / bibliographic reference

Authors: Anikwue R, Huffman JW, Martin ZL, Welch SP.

Year: 2002

Source type: Publication; title and abstract reviewed

DOI: 10.1124/jpet.303.1.340

PMID: 12235269

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

PubMed – bibliographic reference / abstract

DOI – publisher access (access restrictions may apply)

[C_PR_15258190] The THC-induced suppression of Th1 polarization in response to Legionella pneumophila infection is not mediated by increases in corticosterone and PGE2.

Original source / bibliographic reference

Authors: Newton CA, Lu T, Nazian SJ, Perkins I, Friedman H, Klein TW.

Year: 2004

Source type: Primary source, abstract read

DOI: 10.1189/jlb.0304184

PMID: 15258190

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[C_PR_15659311] Vascular effects of delta 9-tetrahydrocannabinol (THC), anandamide and N-arachidonoyldopamine (NADA) in the rat isolated aorta.

Original source / bibliographic reference

Authors: O'Sullivan SE, Kendall DA, Randall MD.

Year: 2005

Source type: Primary source, abstract read

DOI: 10.1016/j.ejphar.2004.11.056

PMID: 15659311

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[C_PR_17284670] The in vitro and in vivo cardiovascular effects of Delta9-tetrahydrocannabinol in rats made hypertensive by chronic inhibition of nitric-oxide synthase.

Original source / bibliographic reference

Authors: O'Sullivan SE, Randall MD, Gardiner SM.

Year: 2007

Source type: Primary source, abstract read

DOI: 10.1124/jpet.106.116566

PMID: 17284670

Source access – 23 October 2026: Source destination was accessible when checked.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[C_PR_18028339] 5-Lipoxygenase and anandamide hydrolase (FAAH) mediate the antitumor activity of cannabidiol, a non-psychoactive cannabinoid.

Original source / bibliographic reference

Authors: Massi P, Valenti M, Vaccani A, Gasperi V, Perletti G, Marras E, Fezza F, Maccarrone M, Parolaro D.

Year: 2008

Source type: Primary source, abstract read

DOI: 10.1111/j.1471-4159.2007.05073.x

PMID: 18028339

Source access – 23 October 2026: Direct retrieval could not be fully verified; availability remains unresolved.

Bibliographic attribution or source identity cross-checked.

DOI – publisher access (access restrictions may apply)

[C_PR_28572770] In Vivo Cannabidiol Treatment Improves Endothelium-Dependent Vasorelaxation in Mesenteric Arteries of Zucker Diabetic Fatty Rats.

Original source / bibliographic reference

Authors: Wheal AJ, Jadoon K, Randall MD, O'Sullivan SE.

Year: 2017

Source type: Primary source, abstract read

DOI: 10.3389/fphar.2017.00248

PMID: 28572770

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

PubMed – bibliographic reference / abstract

PubMed Central – archived text

DOI – publisher access (access restrictions may apply)

[C_PR_31800399] Vasodilatory effects of cannabidiol in human pulmonary and rat small mesenteric arteries: modification by hypertension and the potential pharmacological opportunities.

Original source / bibliographic reference

Authors: Baranowska-Kuczko M, Kozłowska H, Kloza M, Sadowska O, Kozłowski M, Kusaczuk M, Kasacka I, Malinowska B.

Year: 2020

Source type: Primary source, relevant full-text sections read

DOI: 10.1097/hjh.0000000000002333

PMID: 31800399

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

PubMed – bibliographic reference / abstract

PubMed Central – archived text

DOI – publisher access (access restrictions may apply)

[C_PR_34832902] Vasoprotective Endothelial Effects of Chronic Cannabidiol Treatment and Its Influence on the Endocannabinoid System in Rats with Primary and Secondary Hypertension.

Original source / bibliographic reference

Authors: Baranowska-Kuczko M, Kozłowska H, Kloza M, Kusaczuk M, Harasim-Symbor E, Biernacki M, Kasacka I, Malinowska B.

Year: 2021

Source type: Primary source, relevant full-text sections read

DOI: 10.3390/ph14111120

PMID: 34832902

Source access – 23 October 2026: Automated direct retrieval was restricted; this does not establish that the link is broken.

Bibliographic attribution or source identity cross-checked.

PubMed – bibliographic reference / abstract

PubMed Central – archived text

DOI – publisher access (access restrictions may apply)

Research as of 23 October 2026. Not all original full texts could be reviewed in full. Source accessibility and the strength of scientific evidence must be assessed separately. An accessible link does not establish medical approval; a bibliographic record with an abstract does not replace the original full text.

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